Moscow: Speed sensors that were iced over may have caused a Russian passenger jet to crash near Moscow, killing all 71 people on board, the Interstate Aviation Committee said on Tuesday.

In a statement, the committee said a preliminary analysis of black box data made them believe that the pilots` screens were showing the wrong speed as the velocity sensors had frozen, the BBC reported.

A twin-engined Antonov AN-148 model belonging to the Saratov regional carrier departed Moscow`s Domodedovo Airport on Sunday afternoon carrying 65 passengers and six crewmembers en route to the southern city of Orsk before it came down just 80 kilometres southeast outside the capital, near the village of Argunovo.

The plane is believed to have been fully intact until the moment of impact, when it exploded and strewed wreckage across the snowy field in which it crashed.

More than 700 people are involved in the search operation, struggling through deep snow.

The Emergencies Ministry was collecting DNA samples from victims` relatives in order to identify the bodies.